109CY64

109

5,810 千元

2020/08/11

2021/10/10

劉威志

嘉義縣環境保護局

葉美鳳

富立業工程顧問股份有限公司

土壤及地下水

砷

Arsenic

陳慧娟

04-23585953#219

freeair2079@freeair.com.tw

本計畫收集並彙整106年、109年「嘉義縣土壤及地下水污染調查及查證工作計畫」以及環保署「農地砷、汞污染調查及管理策略研析計畫」其中針對嘉義縣進行富砷調查結果，並納入本計畫地下水快篩及全量分析結果，更新繪製嘉義縣地下水機率分佈地圖，以地理統計方式界定出地下水潛勢區邊界，位於嘉義縣東側台南期海進海岸線位置以東區域，統計成果明確為低富砷潛勢，而高富砷潛勢區主要分佈於溪口鄉、六腳鄉、新港鄉、水上鄉、朴子市及義竹鄉，其中以六腳鄉及溪口鄉新增面積最多，接續與「行政院環境保護署地下水砷濃度潛勢範圍查詢平台」富砷區域進行比對，共計24個村里未列入潛勢地圖，多位於六腳鄉，將提供計劃調查數據至環保署作為潛勢地圖更新之資料。 本計畫延續嘉義縣106年例行土水計畫調查方式進行農地踏勘，建立區域性民井資訊、灌溉型態與作物種類，接續進行民井水質砷快篩作業及全量分析調查，藉以限縮引灌富砷地下水坵塊，並執行土壤砷濃度分佈調查，透過評析土壤、地下水調查數據及農民引灌行為。 110年1月下旬完成現勘並建立1,594口民井及100網格資料，由民井調查資料結果顯示，目前民井多分布於朴子市、新港鄉、水上鄉及溪口鄉等鄉鎮，多為民眾私鑿民井，後續將本計畫調查土壤超管制標準之農地及環保局歷年定期監測農地，依「農地土壤砷污染判定及處理原則」計算其判定評分，共13筆坵塊判定結果均為引灌自然成因富砷地下水所致。 本計畫調查10筆農地坵塊，依據引灌民井進行近中遠，三點次土壤重金屬調查，八項重金屬分析僅砷濃度超出食用作物農地監測標準或管制標準，其餘重金屬含量皆符合法規標準，全量分析共有3處農地砷濃度超出管制標準，土壤樣品為S-XK10927-1、S-PZ30505-1及S-MXU0715-1，分別位於溪口鄉、朴子市及民雄鄉，而溪口鄉S-XK10211-1則為超出監測標準，為了解砷濃度縱向分佈情況，本團隊針對裡土(15~30 cm)額外增加30組XRF分析作業，利用調查結果以克利金方式推估濃度分佈，位於表層(0~15 cm)之砷濃度分佈與民井距離皆呈現遞減情況，其餘重金屬則無明顯遞減情形，由上述情況研判土壤砷累積來源，應為引灌民井地下水所致，縱向濃度分佈多數坵塊為裡土濃度減少情況，少數坵塊因農地休耕，或裡作期執行輪耕翻土，裡土濃度高於表土，但此現象之農地表裡土濃度並無太大差異，如需進行改善作業將可依據濃度分佈堆估圖評估其污染土方量，以此基礎計算改善工法所需之經費。 本計畫針對環保局近年定期監測農地，篩選出10筆農地坵塊進行調查，其中大林鎮之兩筆地號及為地下水與地表水兼用之灌溉類型，調查結果顯示出10筆地號皆判定為引灌自然成因富砷地下水所致土壤砷濃度超出管制標準，本次調查共有6筆地號，砷濃度超出土壤管制標準(60 mg/kg)，3筆超出土壤監測標準，建議針對超出管標之地號依據土污法第12條第9項規定將檢測結果通知相關農業、水利及衛生單位目的事業主管機關，並得召開協商會議辦理相關事宜，超出監測標準農地依據環保署之預警年限評估研擬定期監測頻率。 本計畫調查出確實引灌富砷地下水，且具有土壤砷累積現象之農地，進行稻米採樣作業，由歷年環保署專案及農試所研究成果可知，稻米吸收砷之程度與環境介質並非呈現明顯相關性，爰此，本團隊擴大預設情境主動增加稻米檢測數量，調查結果亦顯示出白米或糙米與土壤及地下水間均無顯示出正相關性，而食米中三價砷比例高於五價砷，糙米砷濃度高於白米，此外，針對單一坵塊不同位置稻米採樣之分析成果指出，灌溉水份之差異確實影響稻作砷之吸收。 國土計畫中針對未來農業發展空間及農地分級分類已劃定分佈區域，本團隊已蒐集相關圖資，利用地理資訊系統套疊更新之嘉義縣地下水富砷機率分佈地圖，針對規劃作為稻米生產區之大林鎮、溪口鄉、新港鄉及民雄鄉等鄉鎮，標示出富砷潛勢高機率區域，並建議以優先執行富砷管理及監測對策，提供權責單位作為參考。

砷

期末定稿(公).pdf

33MB

結案報告

2021/12/31 上午 12:00:00

The goal of this project is to continue Environmental Protection Administration, Executive Yuan, R.O.C. (Taiwan)(EPA) natural causes arsenic-rich research project results, combine the Chiayi county calendar year arsenic-rich potential survey data, and focus on the uninvestigated area, that using the area with water after soil survey operating as the core concept. That to update and modify the distribution map of arsenic-rich probability of soil and groundwater in Chiayi County, be helpful to grasp the high-risk areas with an excessive arsenic concentration in soil or groundwater and provide relevant information, administrative management strategies and countermeasures, also applies them to the future spatial development location planning of Chiayi County land plan. The overall project content can be divided into 4 major projects:1.Survey on the distribution and application of groundwater wells. 2.Groundwater and soil sampling analysis. 3.Detection of arsenic content in crops. 4.Results evaluation and geographic statistics. According to the groundwater wells survey results of the distribution and utilization in this project, the civilian wells in Chiayi County are mostly distributed in towns such as Puzi City, Xingang Township, Shuishang Township, and Xikou Township, etc. And they are mostly privately drilled by the public. In addition, this project investigates the farmland that exceeds the control standards and the EPA regularly monitors the farmland over the years, which calculates its judgment score according to the "Agricultural Soil Arsenic Pollution Judgment and Treatment Principles".The calculation result shows that the judgment results of 13 mounds are all caused by irrigation of natural arsenic-rich groundwater. Regarding the farmland surveys, the soil heavy metals were investigated in the near, medium, and far areas according to the irrigation wells. The heavy metal analysis results showed that only the arsenic concentration in the eight heavy metal analyses exceeded the monitoring standards or control standards for edible crop farmland, and the contents of other heavy metals all met the regulatory standards. In addition, the results of soil XRF analysis and Kriging statistics show that the distribution of arsenic concentration in the surface soil (0-15 cm) and the distance from the civilian well show a decline, while the other heavy metals show no significant decline. From this, it could be concluded that the source of soil arsenic accumulation should be caused by the irrigation of groundwater in civilian wells. Regarding the determination of the cause of arsenic-rich, the result of the determination showed that the 10 farmlands selected in this project could be determined as the arsenic concentration in soil caused by natural arsenic-rich groundwater. Therefore, it is recommended to notify the relevant agricultural, water conservancy, and health authorities of the analysis result in the farmland exceed the control standards in accordance with the provisions of the Soil and Groundwater Pollution Remediation Act, and to hold a consultative meeting to handle relevant matters. In addition, the frequency of regular monitoring can be developed for farmland exceeding the monitoring standard based on the evaluation of the early warning period of the EPA. In the crop analysis part, the data has been provided for reference by relevant agricultural units. Finally, the updated arsenic-rich probability distribution map of groundwater from this project shows that the boundary of the groundwater potential zone in Chiayi County is the area east of the Tainan period transgressive coastline on the east side of Chiayi County, which has low arsenic-rich potential, while the high arsenic-rich potential zone is distributed in Xikou Township, Liujiao Township, Xingang Township, Shuishang Township, Puzi City and Yizhu Township, and then compared with the " Platform for querying potential Range of Arsenic concentration in groundwater of Environmental Protection Administration, Executive Yuan" for arsenic-rich areas. , there are still 24 villages in Chiayi County that have not been included in the potential map. Therefore, this project will provide the planned survey data to the EPA as the updated information of the potential map. In addition, although the current national land plan has delineated the distribution area for the future agricultural development space and the classification of agricultural land, this project still uses the geographic information system to overlay the updated groundwater arsenic-rich probability distribution map of Chiayi County. For towns that are planned to be rice production areas such as Dalin Township, Xikou Township, Xingang Township, and Minxiong Township, etc, mark areas with high arsenic-rich potential, suggest priority implementation of arsenic-rich management and monitoring countermeasures, and provide authority and responsibility units as a reference.

Arsenic